Infants and other incontinent individuals wear absorbent articles such as diapers to receive and contain urine and other body exudates. Such articles are intended to prevent body exudates from soiling, wetting, or otherwise contaminating clothing or other articles, such as bedding, that come in contact with the wearer. The most common mode of failure for such products occurs when body exudates leak out of the gaps between the absorbent article and the wearer's leg or waist to adjacent clothing because they are not immediately absorbed within the article. This is most evident with loose fecal material, which is not easily absorbed by the absorbent article.
Several solutions to this problem have been proposed. For example, U.S. Pat. No. 4,490,148 describes an oblong absorbent body having lateral edge portions folded over to form side flaps. The edges of the side flaps contain elastic to contact the thigh creases of the crotch.
U.S. Pat. No. 5,527,303 shows an incontinent pad that has a backsheet with at least one pleat that is tacked with a soluble adhesive so that when the adhesive is wetted, the adhesive dissolves to allow the pleat to expand in conjunction with the absorbent core. A disadvantage to this absorbent article is that the liquid must first pass through the absorbent core before it enters the pleat, if at all. In addition, this absorbent article does not allow for the passage of solid matter into the pleat.
On the other hand, the present invention provides an absorbent article that has an expandable backsheet for collecting liquid and solid matter without it having to first pass through the absorbent core. Where the present invention is in the form of a diaper, a particular advantage is that the void volume of the diaper is increased at the outer surface of the diaper rather than internally, which does not increase the crotch width. Importantly, because the void volume is increased at the outer surface, the space between the wearer and the absorbent core increases with a concomitant reduction in discomfort to the wearer. In addition, the presence of pleats in accordance with the present invention allows the containment of both liquid and solid material without unduly increasing the overall bulk of the diaper.